Effectiveness of Dupilumab for an Elderly Patient with Prurigo Nodularis Who Was Refractory and Contradicted to Traditional Therapy

Introduction

Prurigo nodularis (PN) is a chronic inflammatory skin disease, which is characterized by intractable pruritus and hyperkeratotic nodules. Effective treating options for PN are limited. Systemic therapies (methotrexate, cyclosporine, and thalidomide) are burdened by a high incidence of serious adverse effects, especially in elderly patients.¹ Dupilumab is a fully humanized interleukin (IL)-4Rα antibody. It has been demonstrated to be effective and safe for treating patients with PN with or without atopic history.² Herein we reported a case of elderly patient with refractory PN, and effectively treated with dupilumab.

Case Presentation

An 85-year-old man presented with a 16-year history of PN. He had a history of interstitial lung disease and denied to have atopic background. Physical examination revealed widespread erythematous nodules, plaques, papules, and excoriations on the scalp, extremities, and trunk (Figure 1). Blood tests showed an eosinophil count 0.53×10⁹/L (normal range 0.02–0.50×10⁹/L), total IgE level 242 KU/L (normal range <100.0 KU/L), and a glomerular filtration rate 37 mL/min. This study procedure was given ethical approved by the ethics committees of The First Affiliated Hospital, Zhejiang University School of Medicine (Approved number: IIT20210020A). The patient has given the written informed consent to this case report with all details displayed and the corresponding images.

Figure 1 Clinical presentation of an elderly patient with prurigo nodularis. Prurigo nodularis lesions involving the upper limbs and the trunk at baseline (W0). They were improved after dupilumab therapy at week 12 (W12).

In the past one month, he had been administrated with gabapentin 300mg twice daily, thalidomide 50mg daily, ketotifen 1 mg per night, NB-UVB twice weekly, and topically halomethane cream as needed. However, these treatments failed to relieve his pruritus. Therefore, the patient was transferred from a local hospital to our department. Due to the low glomerular filtration rate (37 mL/min) and interstitial lung disease history, cyclosporine and methotrexate were not recommended to the elderly patient. As suffering from intensive pruritus and low quality of life, this patient was treated with dupilumab with standard doses of 600 mg subcutaneously at week 0 and then 300 mg every other week. During the first 8-week treatment, the patient was continuing to receive cetirizine 10 mg per day, ketotifen 1 mg per night, and topically halomethane cream as needed. Within 12 weeks, the patient gradually achieved improvement of itch intensity measured by visual analogue scale. In order to evaluate the change of cutaneous lesions, we used the tools of investigator’s global assessment and prurigo activity score. The later one represents the patient’s overall disease severity measured by counted number of nodules at the same represented location.³ During the 12-week therapy with dupilumab, reductions were observed in disease severity as assessed on the itch score, prurigo activity score (location: the dorsal site of the trunk), investigator’s global assessment, and Dermatology Life of Quality of Index (Figure 2). No adverse effects were reported during the therapy.

Figure 2 Clinical scores of an elderly patient with prurigo nodularis during dupilumab therapy. (A) The changes of itch severity were measured by visual analogue scale. The changes of cutaneous lesions were assessed by (B) the counted number of nodules in dorsal side of the trunk and (C) IGA. (D) The quality of life was tested by DLQI. Abbreviations: IGA, investigator’s global assessment; DLQI, Dermatology Life Quality Index.

Discussion

It has been identified that the levels of IL-4, IL-13, and IL-31 are increased in lesions of patients with PN.^4,5 Dupilumab inhibits T helper 2 immune response by blocking IL-4 and IL-13 pathway.⁶ Dupilumab is likely to break the itch–scratch cycle of PN through inhibiting these cytokines.

Case series and case reports recently have showed the satisfied efficacy and safety of dupilumab for the treatment of elderly patients with PN (Table 1),^7–11 particularly those failed to traditional therapy. Our case report contributes to the increasing evidence that dupilumab is a therapeutic choice for elderly patients with PN contradicted to traditional therapy.

Table 1 Review of Cases of Elderly Patients with Prurigo Nodularis Treated by Dupilumab

Conclusion

In summary, our case report further suggests that dupilumab could be considered as a potential and well-tolerated treatment option for elderly patients with PN, especially in who were refractory or contradicted to conventional therapy.